This project provides support for the participation of the Radiation Oncology Division of the University of Puerto Rico in the Radiation Therapy Oncology Group. This organization is constituted by a national group of academic insitutions involved in prospective clinical research inradiation therapy of cancer. Study cases are contributed by the University Hospital, the San Juan V.A. Hospital, the San Juan City Hosptial, and the Radiotherapy Insitute of the Metropolitan Hospital, all of which form part of the academic radiation therapy program. Patients with types of cancer pertinent to the RTOG protocols are evaluated and registered in the different studies. Treatment is administered in accordance with protocol requirements and then they are followed indefinitely. Besides case accession, this program contributes new protocols and supervises the work on those protocols. BIBLIOGRAPHIC REFERENCES: Marcial, V.A.: The Role of the Clinician in Community Cancer Control Activities, Am. J. of Roentgenol., 126 (3) 471-474 (1976). Marcial, V.A.: Split-Course Versus Continuous Irradiation (pubished in Spanish), Rev. Argentiana de Radiologia (1975).